Runner Interference

[rwest]

Last year was my first as an ASA Slow Pitch umpire. I had one particular player who would always argue for runner interference. Here's the scenario. Runner at 1b. Batter hits a ground ball to SS who steps on second retiring the runner. The runner is about 5-10 feet off of 2nd when he is put out and does not veer off or duck when the SS makes his throw to 1st. He basically continues toward 2nd without making an effort to get out of the way. He doesn't move into the throw, nor does he veer off or get down.

The player has said to me on two different occassions that the runner has to veer off. I find no such requirement in the rule book. But is this interference?
What do you call? Interference on the runner and the batter-runner out or no call?

Thanks!
Randall